Sniffer dogs will greet passengers from Australia the moment they step off the plane as immediate steps are taken to ward off a recent outbreak of Mediterranean fruit fly in Adelaide.

The Ministry for Primary Industries today announced biosecurity detector dogs would be at the international arrivals gates of all flights from Australia to scrutinise hand luggage that could contain items potentially harbouring fruit fly.

Adelaide is at the centre of a fruit fly outbreak which has seen the South Australian Government impose a quarantine zone in the city.

The fly was discovered in home-grown peaches.

MPI spokesman Craig Hughes said the Adelaide outbreak posed a threat to New Zealand's biosecurity and warranted a decisive response.

"Our intelligence team determined there was a biosecurity threat to New Zealand, so we've swung into gear very quickly," said Mr Hughes.

Using dogs at the arrival gates would mean a greater scrutiny of hand luggage -- the most likely source of fruit and other "risk items" that could harbour fruit fly.

The Adelaide outbreak had also prompted a stricter approach to risk assessment, which meant if there was any doubt, passengers would be x-rayed and have luggage searched.